This application claims the benefit of Korean Application No. 2001-60129, filed Sep. 27, 2001, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an ink cartridge that is used in an ink jet printer, and more particularly, to an ink cartridge in which zigzag air passages are formed at the top of an ink storage chamber, thus preventing the air passages from being clogged due to the backward flow of the ink in the ink storage chamber.
2. Description of the Related Art
FIG. 1 is a plan view of a lid 120 of a colored ink cartridge having five chambers disclosed in U.S. Patent No. 6,086,193. Referring to FIG. 1, the ink cartridge includes five ink chambers: two chambers, which are different from each other in terms of ink concentration, are for each of magenta ink and cyan ink, and one chamber for yellow ink. In the lid 120, five ink filling holes 130 and five air discharging holes 132 are formed to correspond to the five ink storage chambers positioned at the bottom of the lid 120. Also, snake grooves 133 are formed extending in a labyrinth fashion from the air discharging holes 132 to air vents 134a through 134e. Due to the elongated grooves 133, the ink contained in the ink storage chamber can be prevented from evaporating when the inside of each of the ink storage chambers is exposed to the air by taking off a film 135 covering the air vents 134a through 134e so as to use the ink cartridge.
However, in the case of the ink cartridge having the lid 120 with the grooves 133, air passages are easily clogged when the ink cartridge is turned upside-down by mistake or when the ink stored in the ink storage chambers flows backwards via the grooves 133 when the ink cartridge is shaken or overheated. The clogging of the grooves 133 makes it difficult to ventilate the ink cartridge, which results in irregularity in the pressure inside the ink cartridge. As a result, the pressure inside the ink cartridge becomes lower than it should be for stable operation and thus the ink stored in the ink storage chambers is difficult to be ejected.
Accordingly, it is an object of the present invention to provide an ink cartridge of which air passages, which are located at the top of each of ink storage chambers, are not clogged due to the backward flow of ink stored in the ink storage chambers.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and other objects of the present invention are achieved by providing an ink cartridge including an ink storage chamber in which ink is stored, a cover to cover the upper portion of the ink storage chamber and a head to eject ink droplets in the ink storage chamber onto a recording medium, wherein the cover includes an inner cover to cover the upper portion of the ink storage chamber; an outer cover that seals the ink storage chamber and the inner cover, and is positioned at a predetermined distance above the inner cover; and plates to form zigzag air passages by blocking a space between the inner cover and the outer cover.
The inner cover includes air discharging holes connected to the air passages at its upper portion, and air filling holes through which ink is supplied to the ink storage chamber.
The ink cartridge further includes a cylindrical element that extends from the lower part of the inner cover and has a predetermined height.
Further, each of the ink filling holes is sealed by combining a first cylindrical element, which is formed on the inner cover encircling the opening, and a second cylindrical element formed on the outer cover to be engaged with the first cylindrical element.
Further, the inner cover and the outer cover are ultrasonically fused to be combined with each other.